Bubbles are your main means of dominating the world.

When 2 bubbles make contact, the bubble with the larger mass will absorb the bubble with the smaller mass. Your main goal is to absorb opposing bubbles and bring back your bubbles to your home portal.

However, in order to propel your bubbles around the map you must emit smaller bubbles from them. This follows the law of conservation of mass: If you want to go left, you emit a smaller bubble to the right.